1996 Cadillac Seville STS
LACK OF POWER, LOSS OF OIL PRESSURE
Ensure the harmonic balancer bolt is tightened to spec. The correct torque value for this bolt is 60 N.m (44 ft-lb)
plus 120° for 1993-95 engines with an M18 bolt and 50 N.m (37 ft-lb) plus 120° for 1996 engines with an M14
bolt.
NOTE: A small number of 1995 engines were built with crankshafts equipped with the
M14 bolt. Identify the size of the bolt to determine the proper torque
specification.

If the bolt is to specification, the cause of the low oil pressure is internal to the pump.
To remove particles from the relief valve in the oil pump, perform the following procedure:

1. Add an ADDITIONAL 10 to 12 quarts (liters) of engine oil to the engine. This will immerse the pump
completely in oil.

2. Start the engine and repeatedly open the throttle (rev the engine) from idle to 3500 RPM. This will allow
the pump to prime; cycling the relief valve forces any debris from the relief valve.
NOTE: Do not operate the engine above 3500 RPM. Doing so will aerate the
engine oil and/or force excess engine oil into the PCV system. DO NOT
DRIVE THE VEHICLE while the additional oil is in the engine.
NOTE: After the engine has sufficient oil pressure, any valve train noise
associated with this low oil pressure condition should not be evident upon
restarting the vehicle and the low oil pressure and malfunction indicator
lamp (service engine soon) messages should not remain illuminated.

4. Add 7 quarts of engine oil and check the oil level. Make sure the vehicle is on a level surface and the
engine operating temperature is 100°C when checking the oil level with the engine stopped for 15-20
seconds.